First fat help

I am in Australia and researching purchasing my first fat bike I currently ride XC 29 hard tails and want to ride the beaches where my charter boat business Cape York Fly Fishing Charter - Sport Fishing Charters - Cairns Fishing Holiday Queensland Australia operates with the view to getting more fat bikes and offering clients to use them for fishing off the beaches as well as beach combing and general fun. There is limited availability of fat bikes in Aus. Any other fatbike users in Aus on this forum whom can offer assistance as to how to get an alloy frame complete bike here or a frame and the other specific parts I can add the standard components to? I would prefer alloy frame bike/s because of the harsh salt environment and the off set or inline frame question has me leaning toward the inline. Any help or redirection to other threads appreciated.